Roberts Syndrome is an extremely rare genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division,leading to malformation of the bones in the skull,face,arms,and legs.Shown below is a pedigree for a family with Robert's Syndrome.What is the genotype of individual II-C? (R = wild type;r = Robert's syndrome)
A)RR
B)rr
C)Rr
D)R
E)r

Question

Roberts Syndrome is an extremely rare genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division,leading to malformation of the bones in the skull,face,arms,and legs.Shown below is a pedigree for a family with Robert's Syndrome.What is the genotype of individual II-C? (R = wild type;r = Robert's syndrome) 
A)RR 
B)rr 
C)Rr 
D)R 
E)r

Quizplus · Accepted Answer

Individual II-C has Robert's Syndrome, which is a recessive disorder. Therefore, this individual must have two copies of the recessive allele, which is "r." The only genotype that satisfies this condition is Rr. Therefore, the correct answer is C) Rr.

Roberts Syndrome Is an Extremely Rare Genetic Disorder That Is